Merging upstream version 3.0.20.

Signed-off-by: Daniel Baumann <daniel@debian.org>

.github/workflows/test.yaml

@@ -1,39 +0,0 @@
-name: test
-
-on:
-  push: # any branch
-  pull_request:
-    branches: [master]
-
-jobs:
-  test-ubuntu:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9]
-
-    steps:
-      - uses: actions/checkout@v2
-      - name: Setup Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v1
-        with:
-          python-version: ${{ matrix.python-version }}
-      - name: Install Dependencies
-        run: |
-          sudo apt remove python3-pip
-          python -m pip install --upgrade pip
-          python -m pip install . black isort mypy pytest readme_renderer
-          python -m pip install . types-dataclasses  # Needed for Python 3.6
-          pip list
-      - name: Type Checker
-        run: |
-          mypy ptpython
-          isort -c --profile black ptpython examples setup.py
-          black --check ptpython examples setup.py
-      - name: Run Tests
-        run: |
-          ./tests/run_tests.py
-      - name: Validate README.md
-        # Ensure that the README renders correctly (required for uploading to PyPI).
-        run: |
-          python -m readme_renderer README.rst > /dev/null